DENVER — Sewage is probably the last place you’d expect to find a source of valuable metals. But a new report from the U.S. Geological Survey says gold and other precious metals are turning up at wastewater plants.
The report was released at the 249th National Meeting & Exposition of the American Chemical Society this week in Denver.
But don’t plan a treasure hunt just yet.
That’s because the pieces of gold and other precious metals are microscopic.
They typically measure one-hundredth the width of a single hair.
Somehow, all the times we turn on the tap and flush the toilet, we’re also disposing of dollars.
“We found some precious metals such as gold, silver, platinum and palladium, and industrial metals like copper and zinc,” U.S. Geological Survey geochemist Kathleen Smith said.
She found the pricey particles in treated solid waste from eight wastewater plants–some in Colorado.
But where exactly they come from is unknown.
“It’s not just human excrement that goes to a wastewater treatment plant. It’s everything that goes down the drain … and there are metals all over. They are in personal care products. They’re in cosmetics,” Smith said.
Another study from Arizona State said metals flushed by 1 million Americans could be worth $13 million.
But smith said don’t grab a gold mining pan just yet.
“These are not nuggets you’d find in Clear Creek. They are very tiny, tiny particles. So they’d never get them in a gold pan anyway,” she says.
Scientists say knowing these metals exist in solid waste is the first step. Their job now is to figure out how to recover it in a useful form.
“When I think of the actual process, what it takes to retrieve that, it is a really gross thought,” Denver resident Monica Gullihur said.
“I don’t know how they plan on doing it. But whoever they hire to do that I hope they pay them good. Ha, because I’m not digging through no one’s feces,” said Denver resident Davion Finley.
Who could have imagined a virtual gold mine at the other end of the toilet?
One that could also make our country less dependent on metal imports from other countries.
“We import a lot. We could reduce, not replace, but reduce our dependence on some of this,” Smith said.
Also, about half the solid waste we flush through our sewers eventually becomes fertilizer.
If scientists can take the metals out, even more waste could be used in that capacity.